1. Field of the Invention
The present invention relates to a process for forming a wear-resistant, sintered layer on a metallic substrate. More specifically, the present invention pertains to a process for forming on a metallic surface a wear-resistant layer by applying a sheet of wear-resistant alloy particles to the substrate and heat the substrate to a sintering temperature.
2. Description of the Prior Art
Conventionally, it has been known to form a sintered alloy layer on a metallic substrate by applying to the substrate a sheet comprised of alloy particles and a resin binder and heating the substrate to a sintering temperature. For example, in Japanese patent application 50-9398 filed on Jan. 21, 1975 and disclosed for public inspection on July 22, 1976 under the disclosure No. 51-83834, there is disclosed a process wherein an alloy particle sheet comprised of alloy particles dispersed in a binder of thermoplastic acryl resin is attached by means of a suitable solvent such as toluene to the metallic substrate and heated in an atmosphere so that a coating of the alloy particles is formed on the substrate. It should however be noted that the process is disadvantageous in that the alloy particles cannot be satisfactorily supported on the substrate in the progress of the process in a temperature wherein the resin binder is dissipated under heat. Thus, when it is desired to form a coating on an inclined surface, a curved surface or a downwardly faced surface, the alloy particles may fall from the substrate during the process. A further problem in the process is that the alloy sheet has a tendency of shrinking in the sintering process so that there is a difficulty in dimensional control. Thus, it is required to carry out after the sintering process.
In Japanese patent publication No. 55-21802, there is taught to provide a sintered tape by mixing metallic particles such as particles of WC or TiC with a resin binder, shaping into a tape configuration and heating in a press to a sintering temperature, and thereafter attach the sintered tape by means of mechanical fasteners to a mold in which a substrate is molded. However, the process is not advantageous in that increased number of steps are required to carry out the process and that it is difficult to ensure a required adhesive power of the sintered layer to the substrate.